Remove the .dl folder after using Direct Edit on a document

Steps to reproduce:

1. Upload a docx file to Nuxeo
2. Click on the Direct Edit button in the Summary view of the document
3. The docx file is opened in MS Office or LibreOffice
4. Go to the folder .nuxeo-drive/edit and observe that 2 folders have been created :
   • one which ends with "file_content"
   • one which end with ".dl"
5. Finish the edition of the docx file and close MS Office/LibreOffice
6. Close Drive and reopen Drive
7. Observe that the folder which ends with .dl is not removed

Expected behavior: at some point, the .dl folder must be removed as it's the case for the "file_content" folder